Lower gastrointestinal disorders in patients with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal system characterized by abdominal pain related to bowel emptying, defecation impairment and abdominal distention. The aim of the study was to objectify lower gastrointestinal system disturbances in IBS patients. Thirty IBS patients and 30 healthy subjects were included in the study. IBS patients were divided into two subgroups: IBS with predominant diarrhea (IBSd) and IBS with predominant constipation (IBSc). All study subjects underwent physical examination (including digitorectal examination), standard laboratory testing and anorectal manometry. Endoscopy was performed only in group of IBS patients. A statistically significant difference was recorded in most manometric parameters between healthy subjects and IBS patients, which was even more pronounced in IBSd patients. Study results showed that the intestinal motility disorder underlying IBS could be objectified by use of anorectal manometry.     

肠道菌群与肠易激综合征相关研究进展

肠易激综合征(irritable bowel syndrome,IBS)是一种功能性肠病,目前已有研究表明IBS的致病机制、症状的产生和持续时间可能与肠道菌群失调有关,且不同IBS亚型患者体内的肠道菌群种类有差异。IBS的发病机制尚不完全清楚,临床表现存在较大的个体差异。IBS的诊断和治疗尚未形成统一的标准。但已经有较多研究提示IBS可能与胃肠道动力、内脏高敏感性、肠道免疫反应和模式识别受体等密切相关,并且可以通过益生菌、益生元、抗生素、粪菌移植和饮食习惯等调节肠道菌群的失调,从而改善IBS的症状。这也为未来治疗IBS提供了新的思路。本文就肠道菌群的概况、IBS患者肠道菌群的特点、肠道菌群失衡导致IBS发病的可能机制以及IBS肠道菌群的相关治疗方法的研究进展作一综述。     

Composition and temporal stability of gastrointestinal microbiota in irritable bowel syndrome--a longitudinal study in IBS and control subjects

Irritable bowel syndrome (IBS) is a common intestinal disorder that includes continuous or recurrent intestinal pain and discomfort and altered bowel habits. The pathophysiology of IBS is incompletely understood, but it may involve an altered intestinal microbiota. The aim of the present study was to compare the composition and temporal stability of faecal microbiota of IBS patients and healthy controls by applying culture-based techniques and PCR-DGGE analysis. No difference in the prevalence or mean culturable manners of bacteroides, bifidobacteria, spore-forming bacteria, lactobacilli, enterococci or yeasts were observed between the IBS and the control groups, whereas slightly higher numbers of coliforms as well as an increased aerobe:anaerobe ratio was observed in the IBS group. PCR-DGGE revealed more temporal instability in the predominant bacterial population of IBS subjects than in controls. In 9 out of 21 IBS subjects and 5 out of 17 controls the PCR-DGGE profiles obtained from the samples of the same individual on different occasions (sampling points 0, 3 and 6 months) were clearly different. However, the instability in some of the IBS subjects could partly be explained by the antibiotic consumption during the study. The present study suggests that instability of intestinal microbiota may be involved in IBS. However, further studies are needed to associate the instability with specific IBS symptoms or with specific bacterial groups and species.     

Maladjustment to Academic Life and Employment Anxiety in University Students with Irritable Bowel Syndrome

The present study tested our hypothesis that university students with irritable bowel syndrome (IBS) may experience less satisfactory academic lives than those of students without IBS. We also verified the hypothesis that university students with IBS might have higher employment anxiety than students without IBS might. We conducted a cross-sectional study of 1,686 university students. Presence or absence of IBS was assessed via the Rome III Questionnaire. Two original items were used to evaluate academic life. The prevalence rates of IBS with diarrhea, IBS with constipation, mixed IBS, and unsubtyped IBS in the study population were 5%, 2%, 10%, and 3%, respectively. Regarding academic life, the proportions of participants who experienced maladjustment and employment anxiety were 29% and 50%, respectively. After adjusting for age, sex, and faculty, the odds ratios for maladjustment and employment anxiety were significantly higher in students who screened positively, relative to those who screened negatively, for IBS (OR, 1.62; 95% CI, 1.24–2.21; OR, 2.16; 95% CI, 1.68–2.81, respectively). In conclusion, maladjustment and anxiety over future employment were higher in university students with IBS relative to those without.     

Interleukin-8 and -10 gene polymorphisms in irritable bowel syndrome

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal diagnoses seen by primary care providers and gastroenterologists. Proinflammatory cytokines interleukin (IL)-6 and IL-8 have been found increased in IBS patients. Cytokine gene single nucleotide polymorphisms (SNPs) of IL-8 and IL-10 have not been assessed in Mexican IBS patients. DNA was extracted from peripheral blood leucocytes of 45 IBS unrelated patients and 137 controls. Allele, genotype, and haplotype frequencies were determined by analyzing SNPs of IL-8 and IL-10 genes. IL-8 + 396 G allele (P = 0.02), IL-8 + 396(G/G) and IL-8 + 781(C/T) genotypes (P < 0.001), IL-10 - 1082A allele and IL-10 - 1082(A/A) genotype (P < 0.001) were significantly increased in the IBS group. Haplotypes IL-8 ATCC (P = 0.03) and IL-10 ACC (P < 0.001) were associated with susceptibility to develop IBS. An association of certain polymorphisms of IL-8 and IL-10 in IBS patients compared to controls was demonstrated, suggesting a role of these cytokine SNPs in the pathophysiology of IBS.     

High frequency of chronic bacterial and non-inflammatory prostatitis in infertile patients with prostatitis syndrome plus irritable bowel syndrome

Background

Although prostatitis syndrome (PS) and irritable bowel syndrome (IBS) are common disorders, information on the prevalence of IBS in infertile patients with PS is relatively scanty. Therefore, this study was undertaken to estimate the frequency of PS and IBS and to evaluate the prevalence of the various diagnostic categories of prostatitis.

Methodology/Principal Findings

This study enrolled 152 patients with PS, diagnosed by the NIH-Chronic Prostatitis Symptom Index (NIH-CPSI) in an andrological setting, and 204 patients with IBS, diagnosed according to the Rome III diagnostic criteria in a gastroenterological setting. The patients with PS were asked to fulfill the Rome III questionnaire for IBS, whereas patients with IBS were asked to complete the NIH-CPSI. The simultaneous presence of PS and IBS was observed in 30.2% and 31.8% of the patients screened by andrologists and gastroenterologists, respectively. Altogether, 111 patients had PS plus IBS (31.2%). They had a total NIH-CPSI and pain subscale scores significantly higher than patients with PS alone. Gastrointestinal symptoms in patients with PS plus IBS were similar to those reported by patients with IBS alone and significantly greater in patients with PS alone. Patients with PS plus IBS had a significantly higher frequency of chronic bacterial prostatitis (category II) and lower of non-inflammatory prostatitis (category IIIB), compared to patients with PS alone. The frequency of inflammatory prostatitis (category IIIA) resulted similar.

Conclusions/Significance

Prostatitis syndromes and IBS are frequently associated in patients with PS- or IBS-related symptoms. These patients have an increased prevalence of chronic bacterial and non-inflammatory prostatitis.     

Impaired esophageal function in patients with irritable bowel syndrome

The aim of the study was to determine prevalence of the signs and symptoms related to esophageal dysfunction in irritable bowel syndrome (IBS) patients, and to investigate sensorimotor function impairment based on the esophageal manometry study, thus to determine the correlation between them. The study included 30 patients with IBS, 14 of them with diarrhea (IBSd) and 16 with constipation (IBSc) as a predominant discomfort. Control group consisted of 30 healthy subjects. The patients were included in the study on the basis of the Rome criteria for IBS. In addition to thorough history and physical examination patient underwent esophagogastroduodenoscopy and esophageal manometry. The values of esophageal manometry obtained in healthy subjects served as controls in manometry studies. The patients with IBS suffered a great number of both colonic and extracolonic signs and symptoms, however, there was no statistically significant difference in the prevalence of particular symptoms between the two patient subgroups. In comparison with healthy subjects, the patients suffering from IBS showed pathologically altered values in the majority of parameters of esophageal motility. Comparison of the two subgroups of IBS patients according to esophageal motility characteristics yielded differences in only few of them. The results obtained in the study could explain why the patients with IBS quite commonly complain of the symptoms related to upper gastrointestinal tract, such as heartburn and chest pain of noncardiac genesis. The results also suggest that the IBS might be associated with considerably more extensive smooth muscle or innervation changes than presumed before.     

Distinct neurophysiological profiles in irritable bowel syndrome

The objective of this study was to determine whether cortical evoked potentials (CEPs) can define neurophysiological patterns in irritable bowel syndrome (IBS). In this prospective study of consecutive patients attending secondary and tertiary centers, patients with Rome II-defined IBS underwent rectal sensory and pain threshold (RST and RPT, respectively) testing with electrical stimulation on three separate visits. CEPs were collated for 75% pain thresholds, and anxiety [Spielberger State-Trait Anxiety Inventory (SSTAI)] questionnaires were completed. Subjects were 33 IBS patients (27 female, mean age 40.1 yr) and 21 healthy controls (14 female, mean age 31.4 yr). At visit 3, RPT was significantly lower [mean (95% CI)] in IBS patients than in control subjects: 58.2 mA (48.0-68.5) vs. 79.5 mA (69.3-89.6) (P < 0.01). No significant differences were observed in CEP latencies and amplitudes between visits 1, 2, and 3 within each group, except P2 latency for controls (P = 0.04) and N2 latency (P = 0.04) and N2 amplitude (P = 0.02) for IBS patients. Group comparisons showed significant differences in 3-day mean RPT, CEP amplitudes, and CEP latencies between IBS patients and controls. RPT <50 mA and P1 latency >106 ms were identified four IBS subgroups: 24% were hypersensitive, 12% were hypervigilant, 15% were hyposensitive, and 49% exhibited normal P1 latency and pain threshold. CEPs are reliable and reproducible measures of early sensory processing. Identification of four IBS neurophysiological patterns highlights its heterogeneous nature. These findings mark the first step toward personalized medicine in IBS, whereby therapy may be directed at the underlying physiological process.     

IBS症状在溃疡性结肠炎缓解期中的发生情况及影响因素

目的：探讨肠易激综合征（IBs）症状在溃疡性结肠炎缓解期中的发生情况及影响因素。方法：采用问卷调查的形式对来我院就诊的124例溃疡性结肠炎（UC）患者进行调查和随访,对在缓解期的75例患者根据IBS症状的发生情况进行症状评估、心理状态评分,探讨1BS症状在缓解期溃疡性结肠炎患者中的发生情况以及影响因素。结果：溃疡性结肠炎缓解期患者IBS症状的发生率为43％,且女性缓解期溃疡性结肠炎患者出现IBS症状的比例（57％）显著高于男性患者（30％）,而症状达到IBS诊断标准的患者焦虑或者抑郁评分明显高于未达IBS诊断标准者（P〈0．000）。结论：溃疡性结肠炎缓解期患者IBS症状的发生率较高,与患者的心理及精神状态有着密切的关系。     

Remarkable prevalence of coeliac disease in patients with irritable bowel syndrome plus fibromyalgia in comparison with those with isolated irritable bowel syndrome: a case-finding study

Introduction

Irritable bowel syndrome (IBS) and fibromyalgia syndrome (FMS) are two common central sensitization disorders frequently associated in the same patient, and some of these patients with IBS plus FMS (IBS/FMS) could actually be undiagnosed of coeliac disease (CD). The present study was an active case finding for CD in two IBS cohorts, one constituted by IBS/FMS subjects and the other by people with isolated IBS.

Methods

A total of 104 patients (89.4% females) fulfilling the 1990 ACR criteria for FMS and the Rome III criteria for IBS classification and 125 unrelated age- and sex-matched IBS patients without FMS underwent the following studies: haematological, coagulation and biochemistry tests, serological and genetic markers for CD (i.e., tissue transglutaminase 2 (tTG-2) and major histocompatibility complex HLA-DQ2/HLA-DQ8), multiple gastric and duodenal biopsies, FMS tender points (TPs), Fibromyalgia Impact Questionnaire (FIQ), Health Assessment Questionnaire (HAQ), 36-Item Short Form Health Survey (SF-36) and Visual Analogue Scales (VASs) for tiredness and gastrointestinal complaints.

Results

As a whole, IBS/FMS patients scored much worse in quality of life and VAS scores than those with isolated IBS (P < 0.001). Seven subjects (6.7%) from the IBS/FMS group displayed HLA-DQ2/HLA-DQ8 positivity, high tTG-2 serum levels and duodenal villous atrophy, concordant with CD. Interestingly enough, these seven patients were started on a gluten-free diet (GFD), showing a remarkable improvement in their digestive and systemic symptoms on follow-up.

Conclusions

The findings of this screening indicate that a non-negligible percentage of IBS/FMS patients are CD patients, whose symptoms can improve and in whom long-term CD-related complications might possibly be prevented with a strict lifelong GFD.     

Proteomic analysis of colonic mucosa in a rat model of irritable bowel syndrome

Irritable bowel syndrome (IBS) is one of the most common functional disorders of the gastrointestinal tract. It is characterized by abdominal pain and changes in bowel habits. Various studies have investigated the pathophysiologic processes underlying IBS, but the mechanism remains poorly understood. In the present study, we established an IBS model and identified differentially expressed proteins in colon tissue of IBS rats compared with healthy controls by 2‐D gel electrophoresis, MALDI‐TOF‐MS, and Western blot analysis. Our results showed that 13 of the 1396 protein spots on 2‐D gel were differently expressed between the IBS and control groups. Ontological analysis of these proteins revealed primary roles in catalytic activity (protein disulfide‐isomerase A3, glyoxalase I, cathepsin S, α‐enolase), structural support (cytokeratin 8), antioxidant activity (peroxiredoxin‐6), protein binding (transgelin, serpin peptidase inhibitor B5), and signal transduction (40S ribosomal protein SA). Protein disulfide‐isomerase A3 and cytokeratin 8 overexpression in IBS were confirmed by Western blot. The findings indicate that multiple proteins are involved in IBS processes that influence intestinal tract immunity, inflammation, and nerve regulation. Our study provides useful candidate genes and proteins for further investigation.     

Blastocystis sp. in Irritable Bowel Syndrome (IBS) - Detection in Stool Aspirates during Colonoscopy

Blastocystis is one of the most common gut parasites found in the intestinal tract of humans and animals. Its'' association with IBS is controversial, possibly as a result of irregular shedding of parasites in stool and variation in stool detection. We aimed to screen for Blastocystis in colonic stool aspirate samples in adult patients with and without IBS undergoing colonoscopy for various indications and measure the interleukin levels (IL-8, IL-3 and IL-5). In addition to standard stool culture techniques, polymerase chain reaction (PCR) techniques were employed to detect and subtype Blastocystis. All the serum samples collected were subjected for ELISA studies to measure the interleukin levels (IL-8, IL-3 and IL-5). Among 109 (IBS n = 35 and non-IBS n = 74) adults, direct stool examination and culture of colonic aspirates were initially negative for Blastocystis. However, PCR analysis detected Blastocystis in 6 (17%) IBS and 4 (5.5%) non-IBS patients. In the six positive IBS patients by PCR method, subtype 3 was shown to be the most predominant (3/6: 50%) followed by subtype 4 (2/6; 33.3%) and subtype 5 (1/6; 16.6%). IL-8 levels were significantly elevated in the IBS Blasto group and IBS group (p<0.05) compared to non-IBS and non-IBS Blasto group. The level of IL-3 in were seen to be significantly higher in than IBS Blasto group and IBS group (p<0.05) compared to non-IBS. Meanwhile, the IL-5 levels were significantly higher in IBS Blasto group (p<0.05) compared to non-IBS and non-IBS Blasto group. This study implicates that detecting Blastosystis by PCR method using colonic aspirate samples during colonoscopy, suggests that this may be a better method for sample collection due to the parasite’s irregular shedding in Blastocystis-infected stools. Patients with IBS infected with parasite showed an increase in the interleukin levels demonstrate that Blastocystis does have an effect in the immune system.     

阿泰宁治疗肠易激综合征50例的疗效观察

目的 观察和评价阿泰宁（含酪酸梭菌CGMCC NO.0313-1株）治疗肠易激综合征（IBS）的临床疗效.方法 对符合罗马Ⅱ诊断标准的IBS患者,用阿泰宁胶囊口服,1次3粒,1天2次,疗程14～21 d.治疗期间观察患者的症状变化、服药情况,治疗结束后评价药物的疗效.结果 50例IBS患者治疗后的腹泻或便秘等症状有显著的改善（P＜0.05）.治愈率为62%（31/50）,总有效率为94%（47/50）,治疗中未见不良反应或副作用.结论 阿泰宁是治疗IBS的一种安全有效的微生态药品,不但短期应用效果好,而且慢性腹泻或便秘患者可长期服用.     

The Incidence of Other Gastroenterological Disease following Diagnosis of Irritable Bowel Syndrome in the UK: A Cohort Study

Background

Guidelines recommend Irritable Bowel Syndrome (IBS) diagnosis and management in primary care with minimal investigations; however little evidence exists regarding risk of organic gastrointestinal conditions following diagnosis of IBS and how such risks vary over the long term. This study assesses excess incidence of coeliac disease, inflammatory bowel disease (IBD) and colorectal cancer (CRC) and variation with age and time after IBS diagnosis.

Methods

IBS patients and controls were identified within the UK Clinical Practice Research Dataset. Incidence rates were calculated and stratified by age and time since IBS diagnosis with incident rate ratios generated.

Results

Fifteen years after IBS diagnosis there is a significant cumulative excess incidence of coeliac disease, IBD and CRC in IBS of 3.7% compared to 1.7% in controls. For every 10000 patient years, IBS patients experienced an additional 4 diagnoses of coeliac disease, 13 of IBD and 4 CRCs. In each condition peak excess incidence was in the 6 months following diagnosis. After one year, increased incidence of coeliac disease remained consistent without variation by age. IBD incidence fell slowly, with higher rates in those under 30. CRC incidence was increased only in patients aged 30 to 74 during the first 5 years.

Conclusion

Some IBS patients later receive organic gastrointestinal diagnoses, with the early excess incidence likely detected during diagnostic investigation at the time of IBS diagnosis. More than 5 years after IBS diagnosis there is no increased risk of CRC compared to the general population, but a small excess risk of coeliac disease and IBD persists. Overall, though our findings provide reassurance that non-specialists, especially those in primary care, are unlikely to be missing an organic condition in the majority of their patients. This suggests that current guidelines suggesting avoidance of universal referral for these patients are appropriate.     

Cytokines and irritable bowel syndrome: Where do we stand?

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder, which presents with one or more gastrointestinal symptoms without any structural or organic abnormality. The etiology and pathophysiological mechanisms of IBS remain uncertain. Residual or reactivated inflammation at the molecular level is considered the underlying mechanism of post-infectious IBS. On the other hand, genetic variations in the immunological components of the body, including cytokine gene polymorphisms, are proposed as a potential mechanism of IBS even in patients without previous gastrointestinal infection. Several studies have suggested imbalanced cytokine signaling as an etiology for IBS. In this review, recent findings on cytokine profiles and cytokine gene polymorphisms in patients with IBS are described and the role of cytokines in animal models of IBS is discussed.     

Effect of sex on perception of rectosigmoid stimuli in irritable bowel syndrome

In irritable bowel syndrome (IBS) patients, the relationship between sex and sensitivity to visceral stimuli is incompletely understood. Our aim was to evaluate the effect of sex on perceptual responses to visceral stimulation in IBS. Fifty-eight IBS patients (mean age 42+/-1 yr; 34 men, 24 women) and 26 healthy controls (mean age 38+/-3 yr; 9 men, 17 women) underwent barostat-assisted distensions of the rectum and sigmoid colon. Rectal discomfort thresholds were measured using a randomized, phasic distension paradigm before and after repeated noxious sigmoid stimulation (SIG, 60-mmHg pulses). Sex had a significant effect on rectal discomfort thresholds. Women with IBS were the most sensitive (lower thresholds [27+/-2.7 mmHg] and higher ratings), with significantly lower rectal discomfort thresholds compared with men with IBS (38+/-2.3 mmHg) and healthy women who were the least sensitive (41.9+/-3.2 mmHg; both P<0.01). There were no significant differences in rectal discomfort thresholds between healthy men (34+/-4.3 mmHg) and men with IBS. Across both IBS and control groups, women demonstrated a significant lowering of discomfort thresholds after noxious sigmoid stimulation (P<0.01), while men did not. Sex significantly influences perceptual sensitivity to rectosigmoid distension. Women show greater perceptual responses to this paradigm.     

Effects of personality traits on the manifestations of irritable bowel syndrome

Objective

Previous studies have reported that patients with irritable bowel syndrome (IBS) show high neuroticism. However, the precise association between the IBS subtypes and the degree of neuroticism in younger populations is largely unknown. We tested our hypothesis that subjects with diarrhea-predominant IBS may have a higher degree of neuroticism than subjects without IBS or those with other subtypes of IBS. We also verified the additional hypothesis that the severity of neuroticism might be correlated with the severity of IBS in younger populations.

Methods

We conducted a cross-sectional survey of 557 university students, ranging in age from 18 to 21 years. Presence/ absence of IBS and determination of the IBS subtype was by the Rome II Modular Questionnaire, while the severity of IBS was determined by the IBS severity index (IBS-SI). The degree of neuroticism was evaluated using the Maudsely Personality Inventory (MPI). The presence/absence of psychological distress was measured with the K6 scale.

Results

Neuroticism scores in the subjects with diarrhea-predominant IBS were significantly higher than those in the non-IBS subjects or subjects with constipation-predominant IBS. The neuroticism scores were significantly correlated with the IBS-SI scores in all subjects with IBS.

Conclusion

These results suggest that neuroticism is involved in the pathophysiology of IBS in young subjects, especially in that of the diarrhea-predominant subtype.